culiar; and 11thly, _South America_ is the most distinct,
with the exception of Australia, of all the provinces into which the
mammalia can be classed geographically. The various genera of monkeys,
for example, belong to the family Platyrrhini, a large natural division
of the quadrumana, so named from their widely separated nostrils. They
have a peculiar dentition, and many of them prehensile tails, and are
entirely unknown in other quarters of the globe. The sloths and
armadillos, the true blood-sucking bats or vampyres (_Phyllostomidae_),
the capybara, the largest of the rodents, the carnivorous coatimondi
(_Nasua_), and a great many other forms, are also exclusively
characteristic of South America.

"In Peru and Chili," says Humboldt, "the region of the grasses, which is
at an elevation of from 12,300 to 15,400 feet, is inhabited by crowds
of lama, guanaco, and alpaca. These quadrupeds, which here represent the
genus camel of the ancient continent, have not extended themselves
either to Brazil or Mexico; because, during their journey, they must
necessarily have descended into regions that were too hot for
them."[876] In this passage it will be seen that the doctrine of
"specific centres" is tacitly assumed.

_Quadrupeds in Islands._--Islands remote from continents, especially
those of small size, are either destitute of quadrupeds, except such as
have been conveyed to them by man, or contain species peculiar to them.
In the Galapagos archipelago no indigenous quadrupeds were found except
one mouse, which is supposed to be distinct from any hitherto found
elsewhere. A peculiar species of fox is indigenous in the Falkland
Islands, and a rat in New Zealand, which last country, notwithstanding
its magnitude, is destitute of other mammalia, except bats, and these,
says Dr. Prichard, may have made their way along the chain of islands
which extend from the shores of New Guinea far into the Southern
Pacific. The same author remarks, that among the various groups of
fertile islands in the Pacific, no quadrupeds have been met with except
the rat and a few bats as above mentioned, and the dog and hog, which
appear to have been conveyed thither by the natives from New Guinea.
"Rats are to be found even on some desert islands, whither they may have
been conveyed by canoes which have occasionally approached the shore. It
is known, also, that rats occasionally swim in large numbers to
considerable distances."[877]

_Geographical